It is widely known to use an artery graft represented by internal thoracic artery, gastroepiploic artery and radial artery or a vein graft represented by great saphenous vein as a bypass vessel in performing vascular bypass grafting at the heart (coronary artery bypass grafting: CABG). It has also been reported that artery grafts (particularly, internal thoracic artery) offer higher long-term patency rates than vein grafts.
Vein grafts are commonly deemed to be poor in long-term patency rate. In recent years, however, it has been reported that the long-term patency rate concerning a vein graft is enhanced when the vein graft is harvested when being covered with the surrounding tissue (for example, fat, connective tissue, tissue between a skin layer and a muscle layer, tissue between a skin layer and an interosseous membrane, branch vessels, etc.) and is used as a bypass vessel while remaining covered with the tissue.
U.S. Pat. No. 7,981,127 discloses a system to endoscopically harvest a blood vessel in a living body.
In the system disclosed in U.S. Pat. No. 7,981,127, however, a blood vessel and the surrounding tissue (fat) are first dissected by a dissecting device (dissector 3), and then a branch vessel exposed in the living body is stanched and cut by a cutting device (treatment sheath 2). The system of U.S. Pat. No. 7,981,127 is not configured to enable a blood vessel to be harvested together with the surrounding tissue. This system additionally has a drawback in that the stanching and cutting may be conducted by capturing the branch vessel exposed in the living body, and, therefore, workability (i.e., operability) in harvesting the blood vessel is poor.